Père David's deer (Elaphurus davidianus) is a member of the deer family but in China, since her olden days, it was considered to be a mysterious animal whose hoofs resemble somewhat to that of cattle, its head to that of horse, its body to that of ass, and its antlers to that of deer but it does not belong to any of these. Since it became extinct in China, there is no way of ascertaining its native habitat. Those first discovered in China were found in the Imperial Park in Peking where the herd was extirpated by 1900. In 1888 a pair from Peking reached the Uéno Zoological Garden, Tokyo and gave birth to two offspring while one, a female, reached its maturity. Unfortunately however, all the four died one after another toward the end of the Meiji Era, thus no living individual could be found in the Orient.Specimens of Père David's deer preserved in Japan to-day are as follows:-1) A mounted head of a male with antlers and a skull of another with abnormal antlers are preserved in Dr. Hachisuka's collection.2) A complete skeleton of a male a and a skull with antlers are preserved in the National Science Museum, Tokyo.3) A mounted female and an antler are preserved in the museum of the Gakushâin University, Tokyo.In the present article the author fully explains the details of specimens preserved in Japan to-day, introduction and status in the Japanese zoo, the past history in China and subsequent waning of its tribe, reasons why it was considered mysterious, and other points of interest.